One of the first big decisions after installing a new summerhouse is deciding which colour to paint the exterior. A high-quality paint will enhance the appearance and provide long-lasting protection.
When taking delivery of a new summerhouse it will usually come untreated. Without any paint or wood protection applied the timber will be its natural colour and be exposed to the weather and atmosphere. One of the most exciting parts of any new garden building is deciding the colour scheme, whether that’s bright and colourful, or a contemporary design such as anthracite grey and stained wood.
Whichever colour scheme you choose, the type of paint is an important decision. While it may be easy to use a garden fence paint, it will not achieve the level of protection required and will need to be applied each year. Summerhouse exterior paints are one area where you get what you pay for and a premium product is going to offer the best protection for your new garden building. We recommend choosing high-quality paint that will provide peace of mind and protect the building for years to come.
Most modern garden paints are now water-based as opposed to older solvent paint products which give off a strong odour and can lose colour over time. Water-based paints support natural movement in the wood and will flex without cracking and flaking off. A summerhouse will naturally move as it absorbs different levels of moisture from the air throughout the seasons. Before getting started, take a look at our tips below to get the best results when painting a summerhouse.
Best summerhouse paint
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Here is some of our favourite paints for use on summerhouse exterior walls.
Protek Royal Exterior (Amazon)

Long lasting protection and large choice of colours
One of our favourite paint brands for garden buildings is Protek. The brand has been around for over 30 years and supplies a full range of outdoor paints, stains and wood preservers. Royal Exterior is available in over 60 colours (including stains) so there is sure to be a colour suitable for any summerhouse. The paint is only available in specialist suppliers and directly from Protek, but there are several great websites where it can be purchased from online.
Royal exterior provides an exceptionally high-quality finish which allows for minimal maintenance and long-lasting protection. The paint contains UV blockers and creates a weather-resistant coating to protect the timber.
Osmo Country Colour (Amazon)

A durable paint with excellent weather resistance
Osmo is a brand of paint that you know can be relied on. The full range includes a huge number of different wood paints for both interior and exterior use. Osmo Country Colour is a durable and extremely versatile exterior paint that is ideal for garden buildings. The modern microporous formulation reduces cracking and flaking due to natural movement in the timber walls. Protection is provided with excellent UV blocking and weather resistance.
A large selection of over 18 colours is available including cedar redwood, dusk grey and white. A 2.5L tin is the largest size available, and smaller samples can be ordered to patch test the colours.
Sadolin Superdec (Amazon)

A highly recommended opaque wood protection
If you speak to any manufacturers of garden buildings about paint choices, one that is consistently recommended is Sadolin Superdec. This paint provides a water-borne, highly durable opaque finish which is ideal for exterior cladding. The coat can remain flexible to avoid cracking and be used on new or previously painted surfaces.
Sadolin Superdec is self-priming and undercoating, ideal for applying to new timber. A small selection of colours is available including black, white and walnut. Superdec can sometimes be hard to find but is available from a number of specialist retailers online.
Dulux Trade Ultimate Opaque (Amazon)

A solvent-based water repellent coating
Dulux paints are widely trusted and recognised as one of the leading choices for use around the home and garden. Ultimate Opaque is a solvent-based exterior coating formula that combines high performance and great colour. The result is a water-repellent satin finish which looks great on any summerhouse.
The long-lasting protection technology means the exterior is protected for up to 10 years, allowing for minimal maintenance as a summerhouse ages. Several colour choices are available including black and white. Being a Dulux product, there’s good availability from a number of paint retailers.
Why paint a summerhouse?
If you’re a fan of the natural colour of a summerhouse, it may be tempting to leave the natural timber exposed and not apply any paint. Painting can transform the exterior design and allow the building to blend in with the rest of your garden.
But painting a summerhouse is not just about changing the appearance; the crucial reason is to provide long-lasting protection and weather resistance. Timber buildings naturally absorb moisture from the atmosphere around them. The wood is like a sponge, trying to match the level of moisture in the air. When it rains the building can take on water, causing it to expand slightly. In dryer conditions, the wood will hold less moisture, causing it to contract. This natural process of expansion and contraction can cause slight movement in garden buildings, particularly around joints, windows and doors. A wood paint can seal the wood, reducing moisture absorption and keeping it at a constant level.
The British weather can mean winters where water can be left standing for days, with constant rain and wet conditions. A summerhouse where the timber has absorbed moisture and also has poor ventilation can lead to dampness, mould growth and natural decay over time. A high-quality wood treatment will provide protection against damp. For untreated timber, a base coat of wood preserver will prevent fungal growth and protect against wood-boring insects.
Can I use clear paint?
A reason we always paint a summerhouse as soon as possible is to provide UV protection. While a timber building looks great at the start, the natural colour is soon going to fade as it’s exposed to UV from sunlight. Picture a timber fence that has turned grey after not being treated correctly. Paint with coloured pigments inside will cover the wood and provide protection against ageing and UV damage. Look out for paints and wood stains which mention UV protection to avoid the paint also fading over time.
Due to the effect of UV rays, we would avoid using clear paint on a summerhouse. Clear paints and clear wood stains provide no UV protection and will result in the wood starting to turn grey within a few years. If you which to maintain the natural colour of the timber, find a wood stain with the same colour. The pigments inside the wood stain will provide protection against UV and stop the colour fading.

When is the best time to paint a summerhouse?
We often hear people concerned because they have not been able to paint their summerhouse in the week it has been installed. Fortunately, while it does need to be painting quickly, waiting a few weeks won’t do any harm.
We recommend painting a summerhouse within two months of the building being installed. If it’s possible, we would paint it as soon as we have the opportunity. Leaving a summerhouse unpainted for too long may result in some ageing to the wood. If the building has not already been treated, we would at least try to get the base coat on as soon as possible.
The best time to paint a summerhouse is usually on a mild and dry day. The spring and autumn are the best times of the year for painting the exterior. Temperatures above 10 degrees are optimal. But don’t worry if your building arrives in the winter, it’s still okay to paint but may take a bit longer to dry. The painting should always be carried out in dry conditions, choose a time when there’s no rain forecast to give the paint time to dry out completely. If it has been raining heavily in the days before painting, it can be best to allow a few days for the wood to dry out completely and avoid any trapped moisture.
We find the process of painting a summerhouse to be very time consuming and usually takes longer than planned. Remember, for the best finish we often need to apply several coats. Before applying another coat, the first coat must have dried and hardened completely, a process that usually takes 24 hours.
Guide: Does a summerhouse need a vapour barrier?
How to prepare a summerhouse for painting?
A summerhouse does not require much preparation before painting. If the building has been installed for a while, there may be areas on the side of the walls where mud has splashed up during rainfall. A hose or pressure washer can be used to remove any dirt and stop the paint from flaking away once it has been applied.
Paint splashes can get everywhere, especially when painting a large summerhouse. Be sure to use masking tape around the windows and doors to keep them covered up. We recommend using painting sheets around the area being worked on to avoid paint getting onto the summerhouse base or decking. When painting the exterior, start from the top and work downwards to ensure an even and smooth coat is applied.
Do I need a pressure treatment or base-coat?
Summerhouses are made from timber which can be vulnerable to weather conditions, decay and rot over time. Sometimes the option will be available for the summerhouse to be pressure treated before delivery. Pressure treatment involves penetrating the wood with a preservative to provide enhanced protection against rot, decay and fungal attack. A pressure-treated summerhouse will often provide a longer lifespan, ideal for surviving the British weather.

If a summerhouse does not come pressure treated, we recommend using a base-coat to achieve a similar result. Wood Preservers such as Cuprinol Clear Wood Preserver (Amazon) actively protect against rot, decay and fungal attack. We are big fans of this product and apply 2 coats before painting a summerhouse. The wood preserver is clear and designed for painting over the top once it has dried.
What about the interior of a summerhouse?
Painting the interior of a summerhouse can sometimes require different paints to those used on the exterior. The question comes down to the structure of your summerhouse and your planned use for the building. If the summerhouse is a single-skinned structure, with the wood tongue & groove against both the interior & exterior, we recommend using the same paint as the exterior. Continuing to use high-quality paint protects against any water ingress and creates a consistent look & feel.

If you have decided to insulate and line the interior walls of a summerhouse, the choice of paint is larger. When insulating a summerhouse, a vapour barrier should be applied to stop damp building up between the walls. As the interior wall lining will not be touching exterior panels, interior paints can be used. In fact, we have seen many examples of emulsion paint used in insulated summerhouses which are being used as a garden office.
Guide: Which paint to use inside a summerhouse
Can I paint a previously painted summerhouse?
Providing a fresh coat of paint can revitalise an old summerhouse and bring it back to life. The key to getting a good finish on a previously painted building is preparation. An old summerhouse should be completed cleaned first, removing and dirt and fungal growth. Depending on the structural integrity, a pressure washer can be used to clean any hard to remove areas.
If the old paint has not worn sufficiently, it may be difficult for the new products to apply correctly. A fresh base-coat of clear wood preserver should first be applied to provide long-lasting protection to the timber. Once dry, the summerhouse can be painted to give it a clean new look.
Summary
Choosing a summerhouse paint is a big decision that can transform the overall design of your garden building. Paint also provides long-lasting protection and weather resistance to maintain the timber for years to come. Summerhouse paints are an area where it’s best to invest in a quality product to get the best results and avoid regular yearly maintenance.
We recommend avoiding clear paint as it will not provide any UV protection and cause the timber to turn grey over time. A summerhouse should ideally be painted in dry and mild conditions, as soon as possible after taking delivery.
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